Planting trees in your landscape is pretty simple, but it involves more than just digging a hole and popping in a tree.
John Traverso, an arborist and owner of Walnut Creek-based Traverso Tree Service, offered advice to the audience at Our Garden this week on picking, planting and pruning trees. Here are some of his tips:
Think first Before doing anything, take a close look at your yard and where you want to plant trees. Consider the site and the goal. If you want to plant large trees, will there be enough space for them? Are you planting trees for shade or their beauty? Will the tree you want dump a lot of debris in your pool or block your neighbor's view? You need to answer these and other questions before moving on. Know what type of tree you want, then search on the web for lists of trees that have those attributes. Some sites will give you details on the size of the tree, its water requirements, and the life expectancy. Once you have a list, talk to someone who knows trees -- an arborist. Arborists, Traverso says, will help you narrow your list. They are the ones who are taking calls and treating diseased trees, so they can steer you away from troublesome trees as well as recommend hardy ones.
Picking your tree Look for the healthiest tree you can get. Check for shoot growth and make sure the leaves aren't wilted. Check the bud scars, which can tell you how well the tree has been growing. In a 3-year-old tree, for example, if the first two scars are far apart, that indicates the tree grew well in its first two year. But if a third scar is only slightly away from the second, that means the tree didn't grow much in its third year and could be a sign that something isn't quite right. Pick a tree with good structure that has a dominant central leader -- the main, center branch. The dominant leader should be about 50 percent larger than the other branches. Check the root ball. The roots should be spread and lose, not compacted and wound around the tree. Roots become trained and will continue to encircle the tree, eventually killing or weakening it. Plant the tree in a shallow hole, no deeper than the root ball and preferably leaving the root flare (where the tree trunk begins to branch out at the base and form roots) an inch or two above the ground. The width of the hole should be at least twice the size of the root ball. Roots spread mostly horizontally through the ground and go on and on. Roots generally are no deeper than 24 inches, and most of the absorption roots are 6 to 12 inches deep. Planting the tree too deeply smothers the roots, among other things. Fill in the hole with native soil. Do not put amendments in the hole as that will encourage the roots to gird the tree. Young trees may put down a tap root when it is getting established. But once it has, the tap root slowly dies back.
Pruning Leaves provide the food for the tree so in older trees, it's important not to prune them away. A young tree usually can withstand a pruning that removes up to 50 percent of its leaves, but an older, mature tree can't spare a leaf. Pruning an older tree to make it look prettier, Traverso says, is just wrong. You will likely shorten its life.
So far this year, Our Garden has donated just shy of 2,000 pounds of fresh produce to the Monument Crisis Center in Concord.
With the zucchini, squash and beans starting to come in, we expect the numbers to quickly rise.
Our Garden offers free gardening classes 10 a.m. to 11 a.m. every Wednesday, through October. The garden is located at Wiget Lane and Shadelands Drive in Walnut Creek. Master Gardeners are available to answer your questions and diagnose disease and pests, and there is a wide variety of plants for sale.
Next time in the Garden: Saving water in the landscape with Master Gardener Roxy Wolosenko.